President Barack Obama promised Mexican President Enrique Pena Nieto help in the fight against drug cartels and said the United States will keep pressing to expand democracy and human rights in Latin America, including Cuba.

Experts rightfully caution against relying on miracle diet drugs, but a new study offers a novel approach that bears watching. Researchers at the Salk Institute for Biological Studies in La Jolla, Calif., reported Monday that they have developed a...